function getXMLHttpRequest() {
	var request;
	
	if (window.XMLHttpRequest) {
	request = new XMLHttpRequest();
	
	} else if (window.ActiveXObject) {
		try {
		request = new ActiveXObject('Msxml2.XMLHTTP');
		} catch (e) {
		request = new ActiveXObject('Microsoft.XMLHTTP');
		}
	}
	return request;
}

parseResponce = function() {
	if (this.readyState == 4) {
		if (this.status == 200) {
			return this.responseXML;
		} 
		else{
			alert('Error procesando solicitud: \n' + this.statusText);
		}	
	}
};